The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
Cardiac catheterization is a procedure to insert catheters into the heart via an artery or vein to diagnose or treat certain cardiovascular conditions. During cardiac catheterization, a catheter is inserted in an artery or vein in patient's neck, groin or arm. While a radial artery is often used as an access point to the heart during cardiac catheterization, a femoral artery is preferred because it has larger diameter, which allows the insertion of catheters in larger sizes. Once a catheter is properly inserted and positioned, various procedures can be performed by inserting devices into the lumen of the catheter. For example, coronary angiography can be performed by inserting a radio-dense tube to visualize the vasculature structures in the heart. In another example, balloon septostomy can be performed by inserting a balloon catheter to increase the blood flow in a septum of the heart.
Most common complications of cardiac catheterization include bleeding, thrombosis, and vascular trauma. These complications are especially problematic when the sheath of the catheter is relatively large (e.g., more than 8 F), because arterial blood pressure at the site of the insertion is often more than 50 mmHg. Thus, blood spurting from the femoral artery can frequently occur when tubes are disoriented or dissociated from the catheter, or when a health provider replaces an inserted device. While manual compression has been most commonly used to reduce the complication, it requires a significant amount of pressure over the artery, which may cause pain for some patients, and deep vein thrombosis due to femoral artery compression and stasis.
Many technologies have been developed to prevent blood spurting without requiring manual compression over the patient's body. For example, U.S. Pat. No. 5,582,165 to Bryan discloses a catheter connector which is similar to Chinese finger trap. The catheter connector is configured to contract in diameter when the adaptor is pulled or stretched in an axial direction. This reduces blood spurting if the catheter is pulled or slipped out by inadvertent jerking of therapist or patient. U.S. Patent application No. 2004/0012235 to Pinchuk discloses a stretch-valve tube that applies a similar Chinese finger trap mechanism. In Pinchuk, when the flexible valve tube is stretched (e.g., when a urinary catheter is prematurely pulled out), the stretched portion collapses inwardly towards the longitudinal axis as the catheter body lengthens.
Others have sought to solve the problem by mechanically pressing in upon a portion of the catheter. For example, U.S. Pat. No. 7,914,492 to Heuser discloses a catheter introducer system where a portion of the catheter can be shut using a closing system similar to a camera shutter mechanism. In Heuser, a shutter positioned radially about a catheter shutter can be opened by inserting an opening device (e.g., a tip of needle) through the lumen of the catheter, shutter, and then closed automatically when the needle (or other opening device) is removed from the catheter.
All publications identified herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
Thus, there is still a need for improved constriction valve systems for catheters.